Method of marking and producing designs on paper



Patented Nov. 15, 1932 OTTO OI APPLE'ION, WISCONSIN nnirnon or imnxmo AND rnonucme nnsrons on PAPER 1V0 Drawing. Application filed June 5,

This invention relates to a new and improved method of marking and producing designs-n paper.

One of the objects of my invention is to 5 provide an improved method of marking or producing designs on paperthrough the use of a reducing agent applied to the paper by printing or marking the same thereon with a roller carrying the reducing agent and engaging the paper during the production stage of the paper and at a-time just'prior to the complete drying of the paper so that the reducing agent may be dried during the come pletion o the drying f the paper itself. J

Another object of my invention is the provision of an improved method for marking or producing designs in what. isknown as kraft paper, by applying a solution of a reducing agent which has the property of reducing the coloring compounds present in the paper and preferably applying this reducing compound to the-web of paper after it has been partially dried, or dried toa point whereby the molsture contents thereof are about to it being essential that the paper be sufficiently dry so that the solution will not spread when it is transferred to the web of paper by a markin roll, or the like.

A still further object o? my invention is 80 the vprovision of an improved method for .marking or producing designs in i paper through the medium ofthe application of sodium bisulphite, or any similar compound.

plying this solution to the web of paper through the medium of printin or marking rolls, the compound creating a leaching action to produce a design in the paper. This 4 can be carried out either as a separate operation or during the drying of the paper on the machine, so that themanufacturing and marking of the paper can be carried out in one operation. f

As stated in the /objects, my improved method for marking or producing designs on what is well known in the trade as kraft paper, canbe carried out by the use of sodium bisulphite or any compound carrying a sulphur dioxide radical such as sodium hydrosulphite or any bisulphlte, such as a solutlon the paper,

carrying a sulphur dioxide radical and apbeen formed on what-is known as the wet end 1929. Serial no. 868,744.

of calcium bisulphite which has the property of reducing the coloring compounds present in the kraft pulp, or paper.

The well known kraft paper is of a natural reddish or brown color, andby using a compound as disclosed above and applied to a bleaching action will result so that the paper can be readily marked with any desired design. The preferredmethod of producing a design on the paper is to apply a solution of from 1% to 5% of sodium bisulphite to an engraved or marking roller and then engaging this roller with the web of paper after it has been partially dried or at such a time as the moisture contents of the paper will run about 30% to 40%. It is, however, essential that the web of paper be sufliciently dried so that the soluti nof the bisulphite will not s read when, it is transferred to the web 0 paper from the marking or printing roller.

After the solution has been transferred to the partially dried web of paper, the rest of the moisture in the sheet and the moisture from the solution of sodium bisulphite is evaporated on the'balance of the driers, during the manufacture of the paper,' before the paper is wound 'on a reel or cut into sheets according, 0 standard practice at the dry end 8 of the paper machine. J

, It will be noted fromthe foregoing that paper is made on' a variety of machines, but

In all cases the wet ,web of paper after it has of the paper machine, is dried b passing it over suitable rollers and it will e readily apparent that at a predetermined step in the drying operation of the paper, the marking roll to whicha solution of sodium bisulphite has been applied can be engaged with the paper during the drying process. a

"A suitable design or marking can also be produced in the aper by coloring the sheet or paper in the usiial manner as is 'well known in the art and then discharging some of the color by printing the sheet with a solution of bisulphitein the manner described above. In printing designs on colored sheets, the sodium bisulphite'acts as a reducing agent and reduces the aniline dye stuflt's contalned to dissolve the bleaching within the paper to produce colorless or lighter colored compounds, thereby produce ing a marking or design on a colored background.

It will be apparent from the foregoing that I have provided a simple and inexpensive method of marking or producing desi s on colored paper, but preferably what is own on the market as kraft paper which is ordinarily of a natural reddish or brown color and wherein designs can be quickly and readily produced thereon by a plying to the paper, through the medium 0 a marking'or printing roller, a reducing solution which will create a bleaching action on the paper The marking or design :of the paper can be done as a separate operation or on the paper machine towards the dry end of the machine as described. It the marking is to be done as a separate operation the dry paper is printed with a'water solution of a compound containing a sulphur dioxide radical the preferred chemical beingsodium bisulphite. The printing is done by suitable engraved or marked rolls, the paper being'fed in web form from a suitable roll through the printing machine. The excess of water used compound is evaporated on suitable dryers.

While I have described the application of a solution as from 1% to 5% of sodium bisulphite, it will be apparent that the proportion may be varied according to-the type of paper to which the solution is being applied, and also according 'to the design required.

While I have shown and described the preferred embodiment of my invention, it will be apparent from the foregoing that slight,

changes may be made in the steps when putting the invention into practice without departing from the spirit of the same or th scope of the appended claims. Y

I claim:

1. That step in the method of marking paper in a predetermined design, which consists in applyingto a damp .sheet' web 0! paper, a bleaching compound! in predetermined areas, whereby said' a eas will bleached a lighter color than the body of the sheet.

2. Thatstep in the process of marking paper in a predetermined design, which consists in applying sodium bisulphite to a rollerbearing a predetermined design, and applying the roller to a damp Web of paper, as the paper is being dried on the Fourdrinier paper machine.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.

OTTO KRESS. 

